Exhaust-muffler.



PATENTE) FEB. 18, 1903.

No. 879,583-I A. PRATT.

EXHAUST MUFPLER. APPLIoAgrIoN FILED MAY 1a. 1906.

2 SHEETS-SHEET 2.

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WlTNEssrss )wm @ML c?. u @MQW ATTORNEYS 1o. allow the exhaust l hitherto.

30 particularly referred to.

ARTHUR PRATT, oF DUKINFIELD., ENGLAND.

ExalansT-MUFismi:R.l

To 'all whom it may concern.'

Be it known that i, ARTHUR PRATT, sub-y ject of the King of Great Britain and Ireland, and. residing at The Mount, Crescent Road,

5 Dukimield, in the-county of Chester, Eng- :land, have invented newv and useful Improvements in` Exhaust-Muiilers, of whichv A the following is a specification.

The principal object of this invention is to gas on leaving the engine under pressure, to undergo a considerable amount of expansion before it leaves the silencer whereby the sudden impact of the said exhaust as against the atmospheric 15 pressure is great y reduced, vand hence'the silencing7 is much more effective than The exact nature of invention and the manner in which the same is to be .performed or carried into practical effect will be readily understood on reference to` the sheets of drawings annexed and the following explanae tion thereof.

Figure 1.on Sheet 1 of the drawings is a longitudinal section, and' Fig. 2 on Sheet 2,

anend view of the improved exhaust silencer constructed laccording to my invention, and Figs. '3 and 4 are similar views of a modification of the same hereinafter more According to and for the purpose of my invention the bodyof the casing of the silencer is composed of two sheet iron cylinders a and b, one made to lit inside the other,

` with asheet of asbestos, or other suitable nonconducting material or compound between 'Y v them, which also serves to 'muiiie the sound of 1415 rIlhe tubes d an number of `small holes f, f and f2'and are inders a and b are fitted together 40 metal ends c with holes in the center, and through these holes at each end passes a cen`V tral tube d Aand d.` These tubes -are screwed the exhaust gas from the engine. These cylwith cast externally at each end and provided with nuts e, to fix all firmly tofgether. j

d are perforated Awith a tted two iron disks g and g to form stops, one` at'the end of the first group .of L perforationsf, and another at the end of the' 'third group. f 2. Each tube also contains. an internalspira'l or worm h, h on'e at the inlet a;

and the other at'the-outlet. These spirals fit closely into the tubes so that the exhaust gas f passing through the tubes iscompelled totakeaspiral course. 1 A 'Y Fitting closely' onthe center tube d. but so i Specification of .Letters Patent. v

Application filed May 16. 1906- Serial No. 317093.

the central tube d round t top and has a few small holes ma being left for clearance.

through the small holes in' the Patented Feb. 18, 1908.

as to slide. easily backwards and forwards thereon, are -two disks'or stops It* which are perforated with a fewsmall holes, and are rathersmaller in diameter than the inside cylinder b. These' disks are attached to the action of the springs j, j, jg thus causing the chamber to enlarge or expand.- The reaction of the springs will graduallyforce the disks hx back again as the gas passes through the small perforations above mentioned. The gas then passes throu h the holes f into of the holes f 2 into the atmosphere. i

The arrows on the drawing show the direction which the gas takes. The action of this improved silencer causes the exhaust ,to extend over a longer period than heretofore .and entirely does away `witlrthe rapid puffing sound, causing thei exhaust to be ex" tremely silent. 1

As a modification I sometimes pro ose to make the casing of the improved .si encer of a rectangular form in cross-section as shown at Figs. 3 and 4 of the drawings, and instead of the sliding disks or stops hX, at or e spiral h and out near the center of the casingI have a sheet metal flap or doorlc' which 1s hin ed' at the` v (Ie through it.. The interior .of the casing is provided with aA curve or sweepA Z having the same radius as the flap or door 7c, so that the lower end almost `touches it, a small space only 'The inlettube d entering the chamber at one end, and the outlet tube d leaving it at the other. The said tubes are perforated and fitted with internal Worms or s irals h and h as in the previously describe exhaust gas from chamber of the casing throu h the perforations f it moves the door or gap 7c upwards, thuscausingthe chamber to enlarge or expand. The gas then passes more slowly ila and its own weight'brings the hitter `back arrangement. When the or door,

the engine enters the rst f former case causes the exhaust to extend over a longer period, and thus does away with the puffing noise, which usually accoml panies the exhaust in connection with petrol, gas, and oil engines as hitherto constructed.

I claim as my invention 1. An exhaust muffler comprising an expansion chamber, inlet and exhaust ports openin into the same and a flexibly mounted ba e between. said ports, adapted to be actuated by and at all times to ermit the passage of the exhaust vapors to t e exhaust ort. p 2. A11 exhaust muffler comprising an expansion chamber, perforated inlet and exaust tubes opening into the same and a flexibly mounted member adapted to be actuated bythe exhaust vapors interposed in said chamber between the inlet' and exhaust ports.

3. An exhaust muflier comprising an expansion chamber, inlet and exhaust tubes opening into the same, an internal Worm for each of said tubes, and a flexibly mounted.

member adapted to be actuated by the exhaust vapors inter osed in said chamber between the inlet and) exhaust ports.

4. An exhaust muftler comprising an exansion chamber, perforated inlet and exliaust tubes opening into the same, a perforated exibly mounted baie interposed in said chamber between the inletand exhaust ports and adapted to be actuated by the exaust vapors.

5. An exhaust mulier comprising an explansion chamber, perforated inlet and exaust tubes opening into the same and provided respectively with an 4internal worm, a perforated flexibly-mounted baflie interposed in said chamber between the inlet and ex haust ports and adapted to be actuated by the exhaust vapors.

In testimony whereof I .have signed my name to this specification, in the presence of two subscribing witnesses.

ARTHUR PRATT.

Witnesses: Y l.

JNO. HUGHES, J. ERNEST HUGHES. 

